SDLC
The Systems Development Life Cycle (SDLC) is a process used in the development, creation, and maintenance of an information system. This process is often used in the creation or updating of a database system, and can serve as a useful tool for anyone trying to undertake a large database project. __TOC__ Five Phases The System Development Life Cycle (SDLC) has five phases: The Planning phase, the Analysis phase, the Design phase, the Implementation phase and the Maintenance Planning of the SDLC 'Planning' During this phase, the group that is responsible for creating the system must first determine what the system needs to do for the organization (requirements gathering). Often this means asking questions such as.. * What do we need this system for ? * What will the system do for the organization ? * How are we going to make this system ? During this initial phase, resources (both human and technology resources) are put together and a project plan is devised by the project manager. 'Analysis ' The Analysis Phase the second phase of the SDLC and is when the group that has been placed in charge of the project must decide if the project should go ahead with the resources available. This also includes looking at any existing system to see what it is doing for the organization and how well that system is doing its job. The feasibility of the project is also considered, and the group has to ask questions such as... * Can this system be created with the resources (and budget) we have available? * Will this system significantly improve the organization? * Does the old system even need to be replaced? 'Design' The Design stage is the third stage of the System development life cycle and it involves the actual creation and design of a system. This is where they put together the different pieces that will create the system. In a database approach, this would include... Layout is made. * The server hosting the database * The software that will form the database (Access, Oracle, mySQL, etc) * Other needed DBMS (Database Management System) software 'Implementation ' The Implementation Phase is the final phase of the SDLC and it involves the actual construction and installation of a system. This phase also includes the maintenance of the system and any future updates or expansion of the system. With the database project example, the following activities would be common: * Physical installation of the server hosting the database * Installation of the database onto the system * Installation of the Database Management System * Initialization and continuous operation of the database and DBMS * Maintaining the hardware and software hosting the database * Updating the hardware (physical hard drives, etc) and software (DBMS) as needed * Any future expansion of the database. This phase is the longest phase as it has no defined endpoint, with the exception of the end of the system and its users (Amazon shuts down, Google calls it quits, etc). 'Maintenance' The database administrator must be prepared to perform routine maintenance activities within the database. Some of the required periodic maintenance activities include: *Preventive maintenance (backup). Corrective maintenance (recovery). *Adaptive maintenance (enhancing performance, adding entities and attributes, and so on). *Assignment of access permissions and their maintenance for new and old users. *Generation of database access statistics to improve the efficiency and usefulness of system audits and to monitor system performance. *Periodic security audits based on the system-generated statistics. *Periodic (monthly, quarterly, or yearly) system-usage summaries for internal billing or budgeting purposes. Comparison to DBLC The SDLC can be compared to the DBLC with the combination and splitting of a few phases in both systems: Category:Analysis in dbms Category:Ststem development tool in dbms